Typical residential security deposit amount a landlord holds and later accounts for on a return statement in Illinois (2026)
A typical Illinois range, the local factors behind it, and the tools to price your own project.
Reviewed for 2026, updated September 8, 2026.
What drives the cost in Illinois
Illinois deposits track the national typical range statewide, but Chicago and its inner suburbs push well above it, and Chicago also has its own ordinance with rules stricter than the state's. Statewide law applies mostly to landlords with several units: an itemized statement with receipts within about 30 days and the return within about 45, interest requirements for larger buildings that hold deposits more than a few months, and doubled damages for violations, while Chicago's ordinance adds interest, receipt, and disclosure rules of its own, so confirm which set applies to you. Cold winters and freeze-thaw cycles cause pipe, window seal, and radiator issues that are rarely the tenant's fault.
Tips for Illinois buyers
- Determine first whether the property sits inside Chicago; the city ordinance changes the deadlines and the penalties.
- Attach receipts or written estimates to the statement, and if you use estimates, follow up with actual invoices within the period the statute allows.
- Winter turnovers are slow for contractors, so estimates rather than final invoices are often what you send on time.
Ranges are hedged planning estimates derived from a national typical range and a local index, not quotes. A typical single deposit on a market-rate residential rental is commonly around one month's rent, which puts most deposits somewhere in this range; actual amounts vary widely with local rents, unit size, pets, and state caps, and this is a working reference rather than a survey figure.
Price your project
- Deposit Deduction Depreciation Calculator: Estimates how much of a carpet, paint, blind, or appliance replacement a landlord can fairly deduct from a security deposit once the item's age and normal wear are taken into account.
- Security Deposit Refund Statement Calculator: Adds up the deposit held, any interest owed, and each itemized deduction to show the exact refund due to the tenant or the balance the tenant still owes.
- Late Deposit Return Penalty Exposure Calculator: Shows landlords how many days remain before a state return deadline and what missing it could cost when a statute allows forfeited deductions or multiplied damages.